﻿/*
 * Copyright (c) Dominick Baier, Brock Allen.  All rights reserved.
 * see LICENSE
 */

using System;

namespace Thinktecture.IdentityModel.Extensions
{
    public static class DateTimeExtensions
    {
        /// <summary>Converts the given date value to epoch time.</summary>
        public static long ToEpochTime(this DateTime dateTime)
        {
            var date = dateTime.ToUniversalTime();
            var ticks = date.Ticks - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).Ticks;
            var ts = ticks / TimeSpan.TicksPerSecond;
            return ts;
        }

        /// <summary>Converts the given date value to epoch time.</summary>
        public static long ToEpochTime(this DateTimeOffset dateTime)
        {
            var date = dateTime.ToUniversalTime();
            var ticks = date.Ticks - new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero).Ticks;
            var ts = ticks / TimeSpan.TicksPerSecond;
            return ts;
        }

        /// <summary>Converts the given epoch time to a <see cref="DateTime"/> with <see cref="DateTimeKind.Utc"/> kind.</summary>
        public static DateTime ToDateTimeFromEpoch(this long intDate)
        {
            var timeInTicks = intDate * TimeSpan.TicksPerSecond;
            return new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc).AddTicks(timeInTicks);
        }

        /// <summary>Converts the given epoch time to a UTC <see cref="DateTimeOffset"/>.</summary>
        public static DateTimeOffset ToDateTimeOffsetFromEpoch(this long intDate)
        {
            var timeInTicks = intDate * TimeSpan.TicksPerSecond;
            return new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero).AddTicks(timeInTicks);
        }
    }
}